Hi again Joshi,
>
> But I have some questions in mind,
> The amount of signal(concentration of avtivity) emitted by a tissue
> voxel is directly proprotional to the size of a voxel. So
> when I say counts per voxel, I am talking about the concetration of
> activity at that voxel. If I consider that then the calculation
> should be counts per voxel= mci/cc=PET measurement.
First of all there isn't a direct relation between cps and Ci (or
mCi) for that matter. The SI unit Bq means decays/sec, so for that
the relationship is simple.
Also counts (I assume you refer to something that used to be called
"PET counts) is not a measure of how many photons were emitted from a
voxel. It is a measure of how many photons were _detected_ as coming
from that voxel. In general only a tiny teene fraction of the photons
are actually detected in PET, so there will be a non trivial
relationship between counts and kBq/cc (or mCi/cc). I am sure there
is a switch in your reconstruction software to get kBq/cc.
Good luck Jesper
|